guideline 1. initiation of dialysis - NKF KDOQI Guidelines

Theoretical considerations support initiation of dialysis therapy at a GFR of approximately 10 mL/min/1.73 m2, and this was the recommendation of the 1997 ... NKFKDOQIGUIDELINES ClinicalPracticeGuidelinesandClinicalPracticeRecommendations 2006Updates HemodialysisAdequacy PeritonealDialysisAdequacy VascularAccess I. CLINICALPRACTICEGUIDELINESFORPERITONEALDIALYSISADEQUACY GUIDELINE1.INITIATIONOFDIALYSIS 1.1Preparationforkidneyfailure: Patientswhoreachchronickidneydisease(CKD)stage4(estimatedglomerularfiltrationrate[GFR]<30mL/min/1.73m2)shouldreceivetimelyeducationaboutkidneyfailureandoptionsforitstreatment,includingkidneytransplantation,peritonealdialysis(PD),hemodialysis(HD)inthehomeorin-center,andconservativetreatment.Patients'familymembersandcaregiversalsoshouldbeeducatedabouttreatmentchoicesforkidneyfailure.(B) 1.2Estimationofkidneyfunction: EstimationofGFRshouldguidedecisionmakingregardingdialysistherapyinitiation.GFRshouldbeestimatedbyusingavalidatedestimatingequation(Table1)orbymeasurementofcreatinineandureaclearances,notsimplybymeasurementofserumcreatinineandureanitrogen.Table2andTable3summarizespecialcircumstancesinwhichGFRestimatesshouldbeinterpretedwithparticularcare.(B) 1.3Timingoftherapy: Whenpatientsreachstage5CKD(estimatedGFR<15mL/min/1.73m2),nephrologistsshouldevaluatethebenefits,risks,anddisadvantagesofbeginningkidneyreplacementtherapy(KRT).Particularclinicalconsiderationsandcertaincharacteristiccomplicationsofkidneyfailuremaypromptinitiationoftherapybeforestage5.(B) BACKGROUND OptimumtimingoftreatmentforpatientswithCKDpreventsseriousanduremiccomplications,includingmalnutrition,fluidoverload,bleeding,serositis,depression,cognitiveimpairment,peripheralneuropathy,infertility,andincreasedsusceptibilitytoinfection.However,allformsofkidneyreplacementtherapyentailimportanttrade-offs.AsGFRdecreases,patientsandphysiciansmustweighmanyrisksandbenefits.Decisionmakingismorecomplexforolderandmorefragilepatients.Together,patientsandphysiciansmustcontinuallyreconsiderwhethertheanticipatedphysiologicalbenefitsofsoluteclearanceandextracellularfluid(ECF)volumecontrolnowoutweighthephysicalrisksandpsychosocialtolloftherapy.Insomecases,socialandpsychologicalfactorsmaymilitatetoearlierdialysistherapyinitiation,and,insomecases,tolaterinitiation.Theinitiationofdialysistherapyremainsadecisioninformedbyclinicalart,aswellasbyscience,andbytheconstraintsofregulationandreimbursement. Forsomepatients,conservativetherapywithoutdialysisortransplantationistheappropriateoption.10-12Ifthepatientmakesthischoice,thehealthcareteamshouldstrivetomaximizethequalityoflife(QOL)andlengthoflifebyusingdietaryandpharmacologicaltherapytominimizeuremicsymptomsandmaintainvolumehomeostasis.Theseinclude,butarenotlimitedto,useoflow-proteindiets,keto-analogsofessentialaminoacids,loopdiuretics,andsodiumpolystyrenesulfonate.Nephrologistsalsoshouldbefamiliarwiththeprinciplesofpalliativecare13andshouldnotneglecthospicereferralforpatientswithadvancedkidneyfailure. RATIONALE PreparationforKidneyFailure(CPG1.1) TimelyEducationinStage4CKD TimelypatienteducationasCKDadvancescanbothimproveoutcomesandreducecost.14Planningfordialysistherapyallowsfortheinitiationofdialysistherapyattheappropriatetimeandwithapermanentaccessinplaceatthestartofdialysistherapy.PlanningforkidneyfailureshouldbeginwhenpatientsreachCKDstage4,forseveralreasons.Therateofprogressionofkidneydiseasemaynotbepredictable.Thereissubstantialvariabilityinthelevelofkidneyfunctionatwhichuremicsymptomsorotherindicationsfordialysisappear.Patientsvaryintheirabilitytoassimilateandactoninformationaboutkidneyfailure.Localhealthcaresystemsvaryinthedelaysassociatedwithpatienteducationandtheschedulingofconsultations,tests,andprocedures.Resultsofaccesscreationproceduresvary,andthesuccessorfailureofaproceduremaynotbecertainforweeksormonths.Timelyeducationwill:(1)allowpatientsandfamiliestimetoassimilatetheinformationandweighthetreatmentoptions,(2)allowevaluationofrecipientsanddonorsforpreemptivekidneytransplantation,(3)allowstafftimetotrainpatientswhochoosehomedialysis,(4)ensurethaturemiccognitiveimpairmentdoesnotcloudthedecision,and(5)maximizetheprobabilityoforderlyandplannedtreatmentinitiationusingthepermanentaccess. Predialysiseducationtoinformthepatientandsupportpersonsabouttherelativevalueofvariousrenalreplacementmodalitiesoffersafreedomofchoicethatmustbehonored.Educationandchoiceofmodalityalsoarevitaltothetimelyplacementofvascularorperitonealaccess,trainingforhomedialysis,andactualtimingoftheinitiationoftheselectedfirstmodality.Acomprehensivepreemptivediscussionoftheseissueswillenablepatientsandtheirsupportgroupstomakerationaldecisionsandwillservetoinvolvethepatientsasactiveparticipantsintheirpersonalhealthcare.Playinganactiveroleinone'sownhealthcare,althoughthwartingthenaturaldefensemechanismofdenial,reducesrisksfromnegligenceandpsychologicaldepressionthathavebeenassociatedwithpooroutcomesafterdialysistherapyisstarted.15 ContingencyPlans Optimaltimingofvascularaccesscreationmaydependonplansregardingtransplantationand/orPDtreatment.Earlyattemptsatnativeveinarteriovenous(AV)fistulacreationareparticularlyimportantinpatientswhoare:(1)nottransplantcandidates,or(2)lackpotentiallivingkidneydonorsandalsoseemunlikelytoperformPD.Forpatientshopingtoundergo“preemptive”transplantation,avoidingdialysistreatment,thedecisionaboutwhethertoattemptAVfistulacreationatCKDstage4(and,ifso,wheninstage4)dependsonthenephrologist'sestimateofthelikelihoodthatpreemptivetransplantationwillbeaccomplished.ForpatientsinterestedinperformingPD,thedecisiontoattemptAVfistulacreationatCKDstage4dependsonthenephrologist'sestimateoftheprobabilitythatPDwillbesuccessful.ThebenefitsofplanningforkidneyfailuretreatmentarereflectedintheliteraturecomparingtheconsequencesofearlyandlatereferralofpatientswithCKDtonephrologists.16-19 EducationofHealthCareProvidersandFamilyMembers Optimally,educationinpreparationforkidneyfailurewillincludenotonlythepatient,butalsootherindividualswhoarelikelytoinfluencehisorherdecisions.Thesemayincludefamily,closefriends,andprimarycareproviders.Theirunderstandingofsuchissuesastheimpactofinterventionsdesignedtoslowprogression,absenceofsymptomsdespiteunderlyingkidneydisease,transplantationeligibility,choicebetweenPDandHD,andchoiceandtimingofvascularaccessmayhavecriticalconsequencesforthepatient. EstimationofKidneyFunction(CPG1.2) UseofGFR-EstimatingEquationsandClearancesRatherThanSerumCreatininetoGuideDialysisInitiation Variabilityincreatininegenerationacrossthepopulationmakesserumcreatininelevelaloneaninaccuratetestforpatientswithkidneyfailurelikelytobenefitfromdialysistreatment.FormostpatientsinCKDstages4and5,estimatingequationsbasedonserumcreatininelevelandothervariablesapproximateGFRwithadequateaccuracy.Formostpatients,measuredclearancedoesnotofferamoreaccurateestimateofGFRthanpredictionequations.20 VariationinCreatinineGeneration Itiswellestablishedthatcreatininegenerationmaybeunusuallylowinpatientswithanumberofconditionsandthatitmaybeincreasedinindividualsofunusuallymuscularhabitus(Table2).Inthesesituations,GFRestimatedbyusingcreatinineandureaclearancesmaybesubstantiallymoreaccurate(comparedwithradionuclideGFR)thanresultsofcreatinine-basedestimatingequations.Inpatientsforwhomendogenouscreatininegenerationislikelytobeunusuallyloworhigh,GFRshouldbeestimatedbyusingmethodsindependentofcreatininegeneration,suchasmeasurementofcreatinineandureaclearances. VariationinTubularCreatinineSecretion Severaldrugsareknowntocompetewithcreatininefortubularsecretion,andadvancedliverdiseasehasbeenassociatedwithincreasedtubularcreatininesecretion(Table3).DecreasedsecretionwillresultinartifactuallylowGFRestimates,andincreasedsecretionwillresultinoverestimationofGFRbymeansofestimatingequations.Inpatientsforwhomtubularcreatininesecretionislikelytobeunusuallyloworhigh,theconsequentbiastoallcreatinine-basedmeasuresshouldbeconsideredininterpretingGFRestimates. TimingofTherapy(CPG1.3) InitiationofKidneyReplacementTherapy ThisguidelineisbasedontheassumptionthatoverallkidneyfunctioncorrelateswithGFR.Becausethekidneyhasmanyfunctions,itispossiblethat1ormorefunctionswilldecreaseoutofproportiontothedecreaseinGFR.Therefore,caregiversshouldbealerttosignsofdeclininghealththatmightbeattributabledirectlyorindirectlytolossofkidneyfunctionandinitiatekidneyreplacementtherapy(KRT)earlierinsuchpatients.However,theyshouldconsiderthatdialysisisnotinnocuous,doesnotreplaceallfunctionsofthekidney,andthatHD-relatedhypotensionmayacceleratethelossofRKF.ThismayparticularlybetrueofHD. Individualfactors—suchasdialysisaccessibility,transplantationoption,PDeligibility,homedialysiseligibility,vascularaccess,age,declininghealth,fluidbalance,andcompliancewithdietandmedications—ofteninfluencethedecisionaboutthetimingofwhentostartdialysistherapy.ItmaybeoptimaltoperformkidneytransplantationorbeginhomedialysisbeforepatientsreachCKDstage5.EvenwhenGFRisgreaterthan15mL/min/1.73m2,patientsmayhaveamilderversionofuremiathatmayaffectnutrition,acid-baseandbonemetabolism,calcium-phosphorusbalance,andpotassium,sodium,andvolumehomeostasis.Conversely,maintenancedialysisimposesasignificantburdenonthepatient,family,society,andhealthsystem.Thisiscomplicatedfurtherbythepotentialrisksofdialysis,especiallythoserelatedtodialysisaccessanddialysate.TheseconsiderationsnecessitateconservativemanagementuntilGFRdecreasestolessthan15mL/min/1.73m2unlesstherearespecificindicationstoinitiatedialysistherapy.Thus,therecommendedtimingofdialysistherapyinitiationisacompromisedesignedtomaximizeapatient'sQOLbyextendingthedialysis-freeperiodwhileavoidingcomplicationsthatwillreducethelengthandqualityofdialysis-assistedlife. TheoreticalconsiderationssupportinitiationofdialysistherapyataGFRofapproximately10mL/min/1.73m2,andthiswastherecommendationofthe1997NationalKidneyFoundationNKFKDOQIHDAdequacyGuideline.21-23In2003,meanestimatedGFRattheinitiationofdialysistherapywas9.8mL/min/1.73m2.Thismeanvaluereflectsloweraveragevalues(~7to9mL/min/1.73m2)foryoungandmiddle-agedadultsandhigheraveragevalues(~10to10.5mL/min/1.73m2)forchildrenandelderlypatients.AverageGFRatinitiationhasincreasedinallagegroupssince1995;ithasincreasedmostintheoldestpatients.24 ItisdifficulttomakearecommendationforinitiatingKRTbasedsolelyonaspecificlevelofGFR.SeveralstudiesconcludedthatthereisnostatisticallysignificantassociationbetweenrenalfunctionatthetimeofinitiationofKRTandsubsequentmortality.25-28However,otherssuggestedthatworsekidneyfunctionatinitiationofKRTisassociatedwithincreasedmortalityormorbidity.23,24,29Whencorrectionsaremadeforlead-timebias,thereisnoclearsurvivaladvantagetostartingdialysistherapyearlierincomparativeoutcomestudiesofpatientsinitiatingdialysistherapyatahigherversuslowerGFR.30,31 Furthermore,itnowisclearfromobservationalregistrydatafromtheUnitedStates,Canada,andtheUnitedKingdom31AthatpatientswithcomorbiditiesinitiatedialysistherapyathigherlevelsofestimatedGFR.24,32,33Itisreasonabletoassumethatthispracticeisbasedonexperienceandthespeculation,hope,and/orimpressionthatdialysistherapymayalleviateorattenuatesymptomsattributedtothecombinationofthecomorbidityplusCKD.Becausesymptomsofearlyuremiaarefairlynonspecific,onecanexpectthatpatientswithsymptomsassociatedwiththeircomorbiditieswouldinitiatedialysistherapyearly.Healthyandhardypatientswithlesscomorbiditylikelywilldevelopsymptomsatalaterstagethanafrailerearly-startingcomparativegroup.Frailpatientswhostartdialysistherapyearlierdonotliveaslongasthehardypatientswhostartdialysistherapylater.However,thisremainsmerelyaninterpretationofobservationaldata.Amoredefinitiveanswermayemergefromproperlydesignedprospectivetrials.Onesuchtrialexpectstoreportin2008.TheInitiatingDialysisEarlyAndLate(IDEAL)StudyfromNewZealandandAustraliaisaprospectivemulticenterRCTtocompareabroadrangeofoutcomesinpatientsstartingdialysiswithaCockcroft-GaultGFRof10to14versus5to7mL/min/1.73m2.34 In2000,theNKFKDOQIClinicalPracticeGuidelineonNutritioninCKDadvocatedthat—inpatientswithCKDandestimatedGFRlessthan15mL/min/1.73m2whoarenotundergoingmaintenancedialysistherapy—if:(1)protein-energymalnutritiondevelopsorpersistsdespitevigorousattemptstooptimizeprotein-energyintake,and(2)thereisnoapparentcauseforitotherthanlownutrientintake,initiationofKRTshouldberecommended.35Furthermore,thoseguidelinessetforthmeasuresformonitoringnutritionalstatusandidentifyingitsdeterioration.Thoseguidelinesareconsistentwiththepresentrecommendations. LIMITATIONS Individualsvarytremendouslyinthephysiologicalresponsetouremiaandtodialysistreatment.Patientsexpectedtoexperienceuremiccomplicationsoftensurvivemuchlongerthanthephysiciananticipates,withoutapparentadverseconsequences.Patientsalsovaryintheirwillingnessandabilitytoadheretoamedicalregimenintendedtoforestalltheneedfordialysistreatment.Healthcaresystemsandprovidersvarygreatlyintheircapabilitytomonitorpatientswithadvancedkidneyfailuresafelywithoutdialysistreatment.Atbest,thedecisiontoinitiatedialysistreatmentorperformpreemptivetransplantationrepresentsajointdecisionbypatientandphysician,reflectingtheirmutualunderstandingofthecompromisesanduncertainties.Itrequiresclinicaljudgmentbasedonclinicalexperience.